The present disclosure relates to a solid-state imaging device and a manufacturing method thereof, and an electronic apparatus such as a camera including the solid-state imaging device.
As a solid-state imaging device (an imaging sensor), a CCD solid-state imaging device or a CMOS solid-state imaging device and the like are suggested. These solid-state imaging devices are used in a digital still camera, a digital video camera, and various portable terminal devices such as a mobile phone with camera, or the like.
The CCD solid-state imaging device includes photodiodes (photoelectric conversion units) which are two-dimensionally arranged and constitute a plurality of light sensing portions, vertical transfer registers of a CCD structure which are arranged in each light sensing portion column, and horizontal transfer registers of a CCD structure which are disposed at ends of the vertical transfer registers. In addition, output portions are connected to the ends of the horizontal transfer registers.
The CMOS solid-state imaging device forms a unit pixel by photodiodes (photoelectric conversion units) constituting the light sensing portions and a plurality of pixel transistors, and is constituted by two-dimensionally arranging a plurality of pixels. In general, a plurality of pixel transistors is constituted by four transistors of a transfer transistor, an amplification transistor, a reset transistor, and a selection transistor, or three transistors in which the selection transistor is omitted. Alternatively, these pixel transistors can be also used as a plurality of photodiodes. In order to apply a desired pulse voltage to a plurality of the pixel transistors and read a signal current, each terminal of the pixel transistors is connected by a multilayer wiring.
In the solid-state imaging device, an antireflection film for decreasing a light reflectivity is formed on a light sensing surface of the photodiode performing a photoelectric conversion. In the antireflection film, it is necessary to optimize a film thickness, a film kind, a film configuration, or the like in order to decrease the reflection of the light sensing surface.
In Japanese Unexamined Patent Application Publication No. 2000-196051, an example of the antireflection film according to the related art is disclosed. The antireflection film disclosed in Japanese Unexamined Patent Application Publication No. 2000-196051 is applied to the CCD solid-state imaging device, and is provided with a multilayer film structure in which a first high refractive index film, a first low refractive index film, a second high refractive index film, and a second low refractive index film are laminated on a light sensing portion via a gate insulating film. The second low refractive index film is formed by a laminated film of a low refractive index film and an interlayer insulating film. The first high refractive index film is formed of a silicon nitride film, the first low refractive index film is formed of a silicon oxide film, and the second high refractive index film is formed of a silicon nitride film. In addition, a portion of the second low refractive index film is formed of a silicon oxide film. A light shielding film of metal covering a transfer electrode excluding the light sensing surface is formed on the interlayer insulating film which is a portion of the second low refractive index film.